Dear editor,Morphine is considered as a traditional and safe medication to relieve pain and dyspnea in the setting of acute coronary syndrome and cardiogenic pulmonary edema.~([1,2])It is also attributed to dispose an antiarrhythmic effect.~([3])We report a case of morphine-induced ventricular fibrillation in the prehospital emergency treatment.The patient presented acute myocardial infarction with ST segment elevations Dear editor, Morphine is considered as a traditional and safe to relieve pain and dyspnea in the setting of acute coronary syndrome and cardiogenic pulmonary edema. ~ ([1,2]) It is also attributed to dispose an antiarrhythmic effect. 3]) We report a case of morphine-induced ventricular fibrillation in the prehospital emergency treatment. The patient presented with acute myocardial infarction with ST segment elevations